[Bf-blender-cvs] [5f156291cdc] blender-v2.83-release: Fix error scaling thumbnails to zero dimensions

[Campbell Barton]

Commit: 5f156291cdcccba300866e89ef35837093ba52f9
Author: Campbell Barton
Date:   Sat Aug 28 19:57:31 2021 +1000
Branches: blender-v2.83-release
https://developer.blender.org/rB5f156291cdcccba300866e89ef35837093ba52f9

Fix error scaling thumbnails to zero dimensions

Follow up to fix for T89868.

===================================================================

M	source/blender/imbuf/intern/thumbs.c

===================================================================

diff --git a/source/blender/imbuf/intern/thumbs.c b/source/blender/imbuf/intern/thumbs.c
index 17b619d451c..f312ec65bb3 100644
--- a/source/blender/imbuf/intern/thumbs.c
+++ b/source/blender/imbuf/intern/thumbs.c
@@ -435,8 +435,9 @@ static ImBuf *thumb_create_ex(const char *file_path,
         scaledy = (float)tsize;
         scaledx = ((float)img->x / (float)img->y) * tsize;
       }
-      ex = (short)scaledx;
-      ey = (short)scaledy;
+      /* Scaling down must never assign zero width/height, see: T89868. */
+      ex = MAX2(1, (short)scaledx);
+      ey = MAX2(1, (short)scaledy);
 
       /* save some time by only scaling byte buf */
       if (img->rect_float) {